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[/] [openrisc/] [trunk/] [gnu-old/] [newlib-1.17.0/] [libgloss/] [arm/] [redboot-crt0.S] - Blame information for rev 855

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Line No. Rev Author Line
1 148 jeremybenn
 
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    .file   "crt0.S"
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#define XGLUE(a,b) a##b
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#define GLUE(a,b) XGLUE(a,b)
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#ifdef __USER_LABEL_PREFIX__
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#define SYM_NAME( name ) GLUE (__USER_LABEL_PREFIX__, name)
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#else
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#error __USER_LABEL_PREFIX is not defined
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#endif
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    .text
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     /* Setup the assembly entry point.  */
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#ifdef __thumb2__
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.macro FUNC_START name
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        .global \name
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        .thumb_func
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\name:
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.endm
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        .syntax unified
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        .thumb
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#else
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.macro FUNC_START name
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        .global \name
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\name:
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.endm
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        .code 32
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#endif
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        FUNC_START SYM_NAME(start)
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        FUNC_START SYM_NAME(_start)
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        mov     fp, #0  /* Null frame pointer.  */
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        mov     r7, #0  /* Null frame pointer for Thumb.  */
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        /* Enable interrupts for gdb debugging.  */
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#ifdef __thumb2__
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        cpsie if
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#else
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        mrs    r0, cpsr
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        bic    r0, r0, #0xC0
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        msr    cpsr, r0
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#endif
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        mov     a2, #0                  /* Second arg: fill value.  */
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        ldr     a1, .LC1                /* First arg: start of memory block.  */
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        ldr     a3, .LC2
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        sub     a3, a3, a1              /* Third arg: length of block.  */
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#ifdef  GCRT0
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        /* Zero out the bss without using memset.
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           Using memset is bad because it may be instrumented for
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           profiling, but at this point, the profiling data structures
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           have not been set up.
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           FIXME: This loop could be a lot more efficient.  */
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        subs    a3, a3, #0
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        beq     2f
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1:      strb    a2, [a1]
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        subs    a3, a3, #1
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        add     a1, a1, #1
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        bne     1b
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2:
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        /* Nothing to left to clear.  */
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#endif
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#if defined(__thumb__) && !defined(__thumb2__)  /* Enter Thumb mode. */
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        add     a4, pc, #1      /* Get the address of the Thumb block.  */
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        bx      a4              /* Go there and start Thumb decoding.   */
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        .code 16
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        .global __change_mode
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        .thumb_func
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__change_mode:
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#endif
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#ifndef GCRT0
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        bl      SYM_NAME(memset)
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#endif
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        bl      SYM_NAME(__get_memtop)
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        sub     r0, r0, #32
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        mov     sp, r0
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#ifdef __USES_INITFINI__
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        /* Some arm/elf targets use the .init and .fini sections
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           to create constructors and destructors, and for these
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           targets we need to call the _init function and arrange
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           for _fini to be called at program exit.  */
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        ldr     r0, .Lfini
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        bl      SYM_NAME (atexit)
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        bl      SYM_NAME (_init)
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#endif
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        mov     a1, #0
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        ldr     a2, .LC3
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        mov     a3, a2
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        bl      SYM_NAME(main)
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    1:  bl      SYM_NAME(exit)
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        b       1b
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        .align  2
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.LC1:
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        .word   __bss_start__
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.LC2:
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        .word   __bss_end__
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.LC3:
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        .word   0
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#ifdef __USES_INITFINI__
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.Lfini:
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        .word   SYM_NAME(_fini)
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#endif
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#if 0
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#ifdef __thumb__
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        .code 16
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#endif
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        .global SYM_NAME(__syscall)
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#ifdef __thumb__
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        .thumb_func
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#else
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        .align  4
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#endif
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SYM_NAME(__syscall):
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        mov     r12, lr
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#ifdef __thumb__
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        swi     0x18
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#else
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        swi     0x180001
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#endif
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        mov     pc, r12
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#endif

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